Ethernet Virtual Interconnection (EVI) is an Ethernet interconnection technology and is used for the interconnection among user data centers distributed in multiple regions. The EVI can extend Virtual Local Area Networks (VLANs) among different sites and construct independent EVI forwarding instances in the extended VLANs. The EVI forwarding instances are identified with respective network IDs that are numbered uniformly and globally. The packet forwarding in different EVI forwarding instances on a certain device is separated.
A bidirectional EVI tunnel for bearing Ethernet packets is established between Edge Devices (EDs) of different sites in an EVI network. For the bidirectional EVI tunnel between EDs in the same EVI forwarding instance, an EVI link associated with the EVI forwarding instance is established. In this way, the Ethernet packet is forwarded between the EDs in the EVI forwarding instance through two EVI tunnels associated with the same EVI link.